Next story in Afghanistan

KANDAHAR, Afghanistan — Three Taliban suicide bombers disguised in army uniforms stormed a government office in southern Afghanistan on Wednesday after a fourth detonated a car bomb, officials said. At least 17 people — including the four assailants — died.

The Taliban claimed responsibility.

The coordinated assault in Kandahar underscored a new tactic by Afghan militants to launch multidirectional attacks against government offices. It mirrored a February attack in Kabul, where militants assaulted three government buildings simultaneously, killing 20.

Wednesday's attack on Kandahar's provincial council office killed seven civilians and six police officers, President Hamid Karzai's office said. Ahmad Wali Karzai, the head of the council and President Karzai's brother, said the attack came during a meeting of tribal leaders. He said 17 people were wounded.

Among those killed were the province's education director and its deputy health director, Ahmad Wali Karzai said. The president's brother also said he left the council office about five minutes before the attack and was not harmed.

Spate of violenceThe assault comes amid a burst of violence in Afghanistan, where some 60 militants have died in battles the last three days. President Barack Obama — who is deploying an additional 21,000 U.S. forces to bolster the record 38,000 already in the country — has said the United States will increase its focus on the "increasingly perilous" situation in Afghanistan.

The attack began just before noon, when a suicide bomber in a vehicle full of explosives blew himself up at the gates of the council office, opening the way for three other attackers in Afghan army uniforms to storm the building, said Ahmad Wali Karzai.

Karzai told The Associated Press that he was the target of the attack; he did not say how he knew he was the target.

After the car bomb explosion, three militants wearing suicide vests and carrying AK-47 assault rifles entered the compound, said Zemeri Bashary, the Interior Ministry's spokesman. Police killed two of the attackers and the third one blew himself up, Bashary said. A fourth bomber died in the car bomb, bringing the overall death toll to at least 14.

Qari Yousef Ahmadi, a Taliban spokesman, claimed responsibility for the assault and said the target was the provincial compound.

Tribal leaders under threatKarzai said the Taliban is increasingly targeting tribal leaders in their attacks, a tactic militants are also using in Pakistan, he said.

"Now in Kandahar they are using the same tactics," he said. "They've attacked provisional leaders. They are attacking the people who want democracy."

The Kandahar attack came as the Interior Ministry announced that Afghan police and coalition forces killed 31 militants in a Taliban controlled region in a neighboring province, the second large battle in the Afghan south in two days.

The battle took place in three villages in the Kajaki region of Helmand province on Tuesday, the Interior Ministry said. Twenty militants were wounded in the fighting, it said.

Kajaki is the site of a U.S.-funded dam that provides hydroelectric power to much of southern Afghanistan. While a small unit of British troops protects and controls the dam, those forces are surrounded by hostile militants.

Little government controlThe Afghan government admits it has little control in that area of Helmand, the world's largest opium poppy-growing region. U.N. officials estimate that the Taliban and other drug lords derive up to $500 million a year from the trade.

The Kajaki battle was the second large-scale skirmish with militants this week. A police chief in Uruzgan province said Afghan and foreign troops killed 30 Taliban fighters in his province on Monday.

Violence in Afghanistan is expected to surge this year as the new U.S. troops arrive. Militant attacks have grown increasingly deadly the last three years, and insurgents now control wide swaths of countryside where Afghan and international forces don't have enough manpower to maintain a permanent presence.